To inhale a larger quantity of air than usual, and immediately expel it; to make a deep single audible respiration, especially as the result or involuntary expression of fatigue, exhaustion, grief, sorrow, or the like.

2.

Hence, to lament; to grieve.

He sighed deeply in his spirit.
Mark viii. 12.

3.

To make a sound like sighing.

And the coming wind did roar more loud,
And the sails did sigh like sedge.
Coleridge.

The winter winds are wearily sighing.
Tennyson.

An extraordinary pronunciation of this word as sith is still heard in England and among the illiterate in the United States.